| 摘要 |
PURPOSE:To prevent the size of a tightening device from becoming large due to its protrusion from a transmission belt and always apply effective tension to the belt, by installing a part of the tightening device in a dead space inside the transmission belt. CONSTITUTION:In a DOHC-type internal combustion engine, two engine blocks B1, B2 are palced as V and a pair of intake and exhaust valve moving cam shafts 5, 6 are rotatably supported on the cylinder heads 3 of the engine blocks to open and close an intake and an exhaust valves 7, 8. The valve moving cam shafts 5, 6 are rotated by the torque of the crankshaft 1 through transmission chains 15 and so forth. The body 16 of a tightening member is located in contact with the outside surface of the loose part of the transmission chain 15. The static end 17 of the body 16 of the tightening member is pivotally coupled at 19 to an appropriate part of the engine block B1 or B2. The moving end of the body 16 is pivotally coupled at 20 to one end of a rocking arm 21 supported at the other end 31 on a support frame 26 provided in the space S between the cam shafts 5, 6. The rocking arm 21 is energized downward by spring 37. |
